Description

TNF alpha is a multifunctional proinflammatory cytokine that belongs to the tumor necrosis factor (TNF) superfamily. This cytokine is mainly secreted by macrophage and bind to its receptors, TNFRSF1A/TNFR1 and TNFRSF1B/TNFBR. TNF alpha is involved in the regulation of immune cells, cell proliferation, differentiation, apoptosis, lipid metabolism, and coagulation. TNF alpha exists as a multimer of two, three, or five noncovalently linked units, but shows a single 17 kDa band following SDS-PAGE under non-reducing conditions. Knockout studies in mice also suggested the neuroprotective function of TNF alpha, and has been observed to causes tumor necrosis when injected into tumor-bearing mice. Other functions of TNF-alpha include its role in the immune response to bacterial, viral, parasitic and certain fungal infections, as well as its role in the necrosis of specific tumors. TNF alpha causes cytolysis or cytostasis of certain transformed cells, being synergistic with interferon-gamma in its cytotoxicity. This cytokine has been implicated in a variety of diseases, including autoimmune diseases, insulin resistance, and cancer.